Dramatic advancements in nanomagnetic sensor technology, driven by the needs of the magnetic data storage industry, have led to disk drive read heads addressing features 50-100 nm across, at a wholesale cost of about 500 per Gigabyte (8 billion features). An extension of this magnetic recording technology can be used as the basis of extremely powerful biosensors at low cost, while opening the broad and promising field of bio-nanomagnetics. The objective in the proposed work is to build a robust nanomagnetic sensor array capable of sensing sub-50nm magnetic labels and to demonstrate its application to high throughput biomolecular recognition and bio-sensing. The sensitivity of the device to low-abundance mRNAs or proteins is expected to be unprecedentedly high, potentially at the single-molecule level. The ability to base measurements on only one or a few probe and target molecules will improve the quality of the data by suppressing avidity effects arising from multiple interactions, and can reveal genuine single-molecule heterogeneity in target populations not detectable by mass-averaged measurements. The rationale for this research is that such a nanomagnetic sensor array can be based on rapidly-advancing magnetic disk data storage technology, and can be relatively easily integrated into a practical HTS sensor array with extremely high densities of individually-addressable sensors (in the range of 100 million sensors per square millimeter). The research team is especially well-prepared to capitalize on the synergy of recent advances in magnetic data storage and reading technology, the explosive growth in genomics and proteomics, and unique nanofabrication capabilities at the University of Houston. Dmitri Litvinov (PI) has successfully implemented a number of nanomagnetic concepts in commercial magnetic data storage systems, many of which are directly applicable to this project (16 issued patents with Seagate Technology). Richard Wilson (co-investigator) brings to the project his extensive experience in bio-detection and molecular recognition based on DMA probes and antibody affinity. Jack Wolfe (co-investigator) is the world leader in fabrication of ultra-small device structures, with extensive experience in integrated circuit fabrication.